In Orario, fearless adventurers band together in search of fame and fortune within the underground labyrinth known as the Dungeon. But Bell Cranel, novice adventurer, has bigger plans than riches and glory; he fights monsters in the hope of having a fateful encounter with a girl. When this happens, it doesn't go exactly as he planned. Thus begins the story of an unlikely pair, a boy and a goddess, both trying to prove themselves, both eager to reach their goals.
As the labyrinth city of Orario prepares for the Goddess Festival, Bell Cranel looks forward to the festivities after his and Ryu's harrowing escape from the Dungeon's darkened depths. However, in a small tavern tucked away on a street corner, the single decision of a young woman causes a chain of events that throws Bell's life and the entire city into chaos.